Issues with Rocketpoxy/Questions (Oh no! Not another glue thread!!)

[KenECoyote]

My old batch has done this a time or two. Heating it in a water bath and stirring it up made most of it go away. I buy super stout table spoons from the local thrift store.

Thanks!

 

[mtnmanak]

Tom - Sounds like it could be a funky batch.

Not suggesting this as a "solution" - more a curiosity (if you have time) - have you attempted any batches with adjusted resin:hardener ratios? I am thinking a batch with like 1% more hardener and then another batch with 1% more resin. Maybe even a batch or two with slightly more of each. At this point, I would just be interested in the experiment.

I realize you have already wasted a large amount of time and product on experiments, so understand if you are done experimenting with this batch!

 

[Banzai88]

- have you attempted any batches with adjusted resin:hardener ratios? I am thinking a batch with like 1% more hardener and then another batch with 1% more resin. Maybe even a batch or two with slightly more of each. At this point, I would just be interested in the experiment.

This is where I'm headed next, if I don't just move into acceptance and use it.

 

[David Schwantz]

Thin it with alcohol. I was just doing this for some fillets. Seems to really smooth it out.

 

[mtnmanak]

This is where I'm headed next, if I don't just move into acceptance and use it.

If it makes a difference, it may be useful feedback to Glenmarc. If either the resin or the hardener is less efficacious you would expect they would like to know their G5000 product has got an issue, at least for that batch.

 

[Banzai88]

If it makes a difference, it may be useful feedback to Glenmarc. If either the resin or the hardener is less efficacious you would expect they would like to know their G5000 product has got an issue, at least for that batch.

Yep, I already have a draft email that I'm working on attaching pictures to (even if the pics aren't of much value overall).

 

[Rocketclar]

Seems like resin is suspect due to age or self reacting or simply bad. I've had similar issues with JB Weld clear resin and Aeropoxy resin thickening and developing cloudiness and globs eventually hardening on its own.

 

[jsdemar]

There's nothing special about Rocketpoxy. It's just another generic 1:1 resin:hardener will fillers in the hardener to get the 1:1 ratio. Slight differences can happen when decanting from the large source drums into the consumer bottles. Moisture can also effect the ratio.

I realize it's expensive to use the larger bottles of industrial/marine epoxies, and they can age also. But, I've been using US Composites epoxies for many years without problems. You get to choose the fillers for various purposes. Extremely strong results.

A friend had his L3 rocket (4" rocket with 3" motor) come apart using Rocketpoxy. Some surfaces were still sticky after weeks.

 

[DaHabes]

JUST TO ADD SOME "POSSIBLE BACKGROUND"...
ANYTHING that has to due with resins has been VERY disrupted by the pandemic and supply chain issues. We use custom manufactured epoxy at work. We have had to pay a $3000-5000 surcharge (yes 3-5k EXTRA) to make a 5 gal batch of harder. We also have had to work with the manufacturer to "reformulate" it twice, due to component supply issues. This is a BIG deal for industry.

I would be willing to bet at the basic chemistry level there are some changes in a LOT of epoxies. If the original purchasing company and manufacturer feel it is equivalent, they likely don't tell down stream customers of the changes. (THEY ARE ALL PROPRIETARY, AND NOT DISCLOSED ANYHOW.)

We have seen some residue on the surface of freshly cured items. It's likely humidity in the air reacting with some components. Give it 3-5 days to finish curing and wipe with alcohol or acetone. The other option is a moderate temperature "post cure" for a few hours after the initial 24 hour room temp cure. This will drive off the moisture, and finish the cure. The surface will likely not get that coating again, even in high humidity environments.

[ Edit : To make it perfectly clear; I have NOTHING to due with any of the specific epoxies, or manufacturers, in this thread. It is ALL SPECULATION, based on some industry exposure. ]

This makes a lot of sense. I bought my second batch of RP last year, my first batch in 2020 or 2019. The consistency of the epoxy and hardener in the 2 batches were completely different. In the first batch the epoxy has thick and the hardener thinner (& flowed better). In the 2nd batch it was the exact opposite. The 2nd batch was basically the same once mixed and setup the same, but there were definitely differences.

 

[cwbullet]

A friend had his L3 rocket (4" rocket with 3" motor) come apart using Rocketpoxy. Some surfaces were still sticky after weeks.

I have never had that happen. I wonder if that might be an environmental difference.

 

[Chad]

maybe it was your finger that was sticky and not the RP?

 

[Banzai88]

I sent an email to Glenmarc Industries, the makers of RocketPoxy. They've responded with a series of questions, which I answered, and said that they'll have some of their engineering folks pull samples from those batch numbers, run some tests, and get back to me.

 

[Handeman]

Question about Rocketpoxy. Since the solids settle to the bottom of the white resin container so fast, what is everyone doing to get the solids scraped off the bottom and mixed back into the resin, especially when the container is almost full? Any shortcuts, or is it just a lot of mixing and stirring required?

 

[Banzai88]

Question about Rocketpoxy. Since the solids settle to the bottom of the white resin container so fast, what is everyone doing to get the solids scraped off the bottom and mixed back into the resin, especially when the container is almost full? Any shortcuts, or is it just a lot of mixing and stirring required?

I recently did just this. I heated the tubs in a water bath to 100F and used a pair of super stout spoons purchased from the thrift store to stir, stir, stir, stir. Took all of about 20 minutes, start to finish.....but it still didn't change how my current new batch is performing.

 

[4regt4]

How are you guys measuring Rocketpoxy? I just mix up small quantities, and it's difficult to dig the stuff out of the jar with popsicle sticks, or whatever. I don't see a way to actually measure it, weight or volume. I've been eyeballing the big globs hanging from the popsicle sticks and hoping for the best. So far I guess I've been lucky, as it has always solidified fine. I suppose it would be easier to measure if I were mixing up larger quantities.

With thinner liquid epoxy, I can either measure in a cup, or put it on my scale. But it's hard to do that with something resembling chewing gum.

Hans.

 

[kswing]

How are you guys measuring Rocketpoxy? I just mix up small quantities, and it's difficult to dig the stuff out of the jar with popsicle sticks, or whatever.

I've done some smaller amounts just eyeballing it with blobs on cardboard and so far it has worked ok.

For larger volumes, to be more precise, I use two pieces of cardboard and a small scale. I put the cardboard on the scale and zero it and then use a tongue depressor/popsicle stick to put a blob on the cardboard and note the weight. I set that piece aside and then do the same for the other part and adjust as needed so the epoxy weights match (within 1/100 of an ounce). After that I use a bigger piece of cardboard or some spare poster board and scrape both blobs onto it for mixing.

 

[thzero]

How are you guys measuring Rocketpoxy?

https://www.amazon.com/Coopay-Plast...1674696564&sprefix=epoxy+cups,aps,123&sr=8-12

 

[Handeman]

I bought a stack of 4" paper plates at the dollar store that I put on the scale. I usually fold up one side so I can see the scale readout. I put enough of the first part on the plate and then add the second until the weight is doubled. 10 - 15 grams of each part goes a long ways.

 

[4regt4]

I bought a stack of 4" paper plates at the dollar store that I put on the scale. I usually fold up one side so I can see the scale readout. I put enough of the first part on the plate and then add the second until the weight is doubled. 10 - 15 grams of each part goes a long ways.

I've tried doing that, but the stuff is so thick that I can't seem to be able to get accurate amounts. i.e. I under or over shoot and it's hard to adjust it.

Hans.

 

[Handeman]

I've tried doing that, but the stuff is so thick that I can't seem to be able to get accurate amounts. i.e. I under or over shoot and it's hard to adjust it.

Hans.

It is kind of a pain, but I do the brown hardener first, the white resin flows better so you can let it drip off a stick slowly and cut it off with another stick to get it pretty close. It's not like it has to be ±0.1gram. I'm usually good if it's within a gram of the doubled weight I'm looking for, or about 5% of the total I'm looking for. i.e. 15g of hardener and 14-16g of resin.

 

[cautery]

Question about Rocketpoxy. Since the solids settle to the bottom of the white resin container so fast, what is everyone doing to get the solids scraped off the bottom and mixed back into the resin, especially when the container is almost full? Any shortcuts, or is it just a lot of mixing and stirring required?

I store containers with suspensions on their heads, so that when I open to stir, the contents that have settled are on the TOP and naturally mix down as I stir.

As to the mixing question....
I have a couple of super accurate gram/grain scales for reloading, and an O'Haus triple beam scale for larger quantities.
I ONLY mix by weight.

 

[Banzai88]

OK, it's been a week now and no further information from Glenmarc......so I moved on to ordering another set from Tim at Wildman. I just got it all stirred last night and it's settling today and I'll do up my normal test batches and see what's up.

As an interesting note, the new resin is the same batch number as I had been using, but the hardener is a different batch than what I got from Apogee.

Going back to my original test batches, which is now just shy of 3 weeks old and a few of them are FINALLY what I would call a 'normal' cure. At least 2 of the samples (both from different mixes) are still 'sticky' to a very minor degree.

Still, it's orders of magnitude different than all my previous experience with RP, which I normally experience being fully cured with no stickiness in 24 hours or less.

 

[cwbullet]

Does anyone know if Rocketpoxy will stick to plastic?

 

[Banzai88]

Does anyone know if Rocketpoxy will stick to plastic?

What type of plastic? As in PLA or blow molded nose cones? Yes to both, in my experience, but I always use 60 grit surface prep to make sure there is a lot of mechanical surface. Never had something break free or shed the RP.

 

[cwbullet]

What type of plastic? As in PLA or blow molded nose cones? Yes to both, in my experience, but I always use 60 grit surface prep to make sure there is a lot of mechanical surface. Never had something break free or shed the RP.

I am making my centering rings out of PETG.

 

[thzero]

I am making my centering rings out of PETG.

I've had ok with PETG; same techniques as banzai.

 

[cwbullet]

I've had ok with PETG; same techniques as banzai.

Thanks- I will try it.